Working on the Neon816

This commit is contained in:
mgcaret 2019-12-04 21:18:42 -08:00
parent e73066a53f
commit e79e2974e5
8 changed files with 166 additions and 65 deletions

2
.gitignore vendored
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@ -10,4 +10,6 @@ t
*.po
romfs
.DS_Store
*.hex
of816-neon.bin

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@ -1,6 +1,31 @@
; Bank Map from FB posting by Lenore:
; 00 Bank Mapper (16 blocks of 4k each, configured via MMU)
; 08-0F Bus Controller Peripherals
; - 08 0000-003F MMU
; -- 00: 0-3 Unused, 4-7: Upper RAM bits
; -- 01: Bank
; - 09 FDC
; 10-1F Internal Bus Bridge
; 20-27 Flash ROM
; 28-3F Reserved for Flash
; 30-3F Reserved for Expansion Flash
; 40-47 Video RAM
; 48-7F Reserved for VRAM
; 80-87 RAM 1
; 88-8F RAM 2
; 90-FF Reserved for RAM
cpu_clk = 14000000
; *****************
; Memory regions
; *****************
Neon_ROM = $200000
Neon_VRAM = $400000
Neon_RAM1 = $800000
Neon_RAM2 = $880000
; *****************
; MMU
; *****************

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@ -1,16 +1,18 @@
FEATURES {
STARTADDRESS: default = $0000;
STARTADDRESS: default = $200000;
}
MEMORY {
ROM: start = $0000, size = $10000, file = %O;
ROM: start = $200000, size = $10000, fillval=$FF, file = %O;
ZP: start = $0000, size = $100;
}
SEGMENTS {
FStartup: load=ROM,type=ro;
FSystem: load=ROM, type=ro;
FCode: load=ROM, type=ro, optional=yes;
FStartup: load=ROM, type=ro, fillval=$00;
FSystem: load=ROM, type=ro, fillval=$00;
FCode: load=ROM, type=ro, fillval=$00, optional=yes;
ROMBOOT: load=ROM, type=ro, offset=$FF00;
VECTORS: load=ROM, type=ro, offset=$FFE0;
ZEROPAGE: load=ZP, type=bss;
}

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@ -7,65 +7,31 @@
.import _Forth_ui
.import _system_interface
; Bank Map from FB posting by Lenore:
; 00 Bank Mapper (16 blocks of 4k each, configured via MMU)
; 08-0F Bus Controller Peripherals
; - 08 0000-003F MMU
; -- 00: 0-3 Unused, 4-7: Upper RAM bits
; -- 01: Bank
; - 09 FDC
; 10-1F Internal Bus Bridge
; 20-27 Flash ROM
; 28-3F Reserved for Flash
; 30-3F Reserved for Expansion Flash
; 40-47 Video RAM
; 48-7F Reserved for VRAM
; 80-87 RAM 1
; 88-8F RAM 2
; 90-FF Reserved for RAM
.pushseg
.segment "FStartup"
.proc startup
clc
xce
rep #SHORT_A|SHORT_I
.a16
.i16
; MMU setup, maybe. Found at page $FF in Neon bank 0
ldx #$001C
lda #$8000
: sta f:NeonMMU,x
dex
dex
bpl :-
; NeonFORTH does this, presumably to initialize the serial port
sep #SHORT_A ; not necessary unless we were already native & long
.a8
lda #$8D
sta f:SERctrlA
lda #$06
sta f:SERctrlB
lda #$00
sta f:SERctrlC
phk
plb
rep #SHORT_A|SHORT_I
.a16
.i16
lda #$0000 ; direct page for Forth
tcd
lda #.hiword($0A0000) ; top of dictionary memory
lda #.hiword(Neon_RAM1+$020000) ; top of dictionary memory
pha
lda #.loword($0A0000)
lda #.loword(Neon_RAM1+$020000)
pha
lda #.hiword($090000) ; bottom of dictionary
lda #.hiword(Neon_RAM1+$010000) ; bottom of dictionary
pha
lda #.loword($090000)
lda #.loword(Neon_RAM1+$010000)
pha
lda #$0200 ; first usable stack cell (relative to direct page)
lda #$0400 ; first usable stack cell (relative to direct page)
pha
lda #$0100 ; last usable stack cell+1 (relative to direct page)
lda #$0204 ; last usable stack cell+1 (relative to direct page)
pha
lda #$03FF ; return stack first usable byte
lda #$01EF ; return stack first usable byte
pha
lda #.hiword(_system_interface)
pha
@ -73,7 +39,6 @@
pha
jsl _Forth_initialize
jsl _Forth_ui
brk
.byte $00
jmp startup
.endproc
.popseg

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@ -1,21 +1,66 @@
# Neon816
This is a port to Lenore Byron's [Neon816](https://hackaday.io/project/164325-neon816)
system. The Neon816 Developer Edition ships with a small 16-bit Forth.
This is a port to Lenore Byron's [Neon816](https://hackaday.io/project/164325-neon816) system. The Neon816 Developer Edition ships with a small 16-bit Forth.
At the time of commit 91af87fa4e42dced1d22d3cb620e84e6edb91817, OF816 for the Neon816
is configured to run out of any available ROM bank at starting address $0000. It configures
the MMU hopefully like NeonFORTH does, sets the data stack from $0000-$01FF and the return stack from $0200-$03FF. It hopefully also configures the serial port.
OF816 for the Neon816 is configured to run as an alternative firmware out of bank $20. With a little ajustment, it could be configured to run out of bank $21 (but starting it is an excercise for the reader).
It configures the MMU and serial port like NeonFORTH does. The direct page, stack, and return stack occupy the first $400 bytes of RAM.
To build OF816 for the Neon816, change to the platform directory and run
build.sh. It will output a binary named "forth" that can be started at address $0000 of the
bank it is loaded into.
At this point nothing further can be done until we have the ability to use the debug port to
load OF816 into the flash ROM.
``build.sh``. It will output a 64K binary named ``of816-neon.bin`` that can be flashed into the Neon's firmware. See below for installation instructions.
## Port Features
Hopefully this section will be filled up with stuff that works like Lenore's
Forth. See the [Neon816 Manual](https://cdn.hackaday.io/files/1643257030480800/sysmanual.pdf)
Forth. See the [Neon816 Manual](https://cdn.hackaday.io/files/1643257030480800/sysmanual.pdf). But right now, it's just a bare port with no system-specific extensions.
## Installation
**THIS WILL OVERWRITE THE NEON'S ORIGINAL FIRMWARE.**
**IT IS STRONGLY RECOMMENDED YOU BACK UP THE ORIGINAL FIRMWARE**
**READ _ALL_ OF THE FOLLOWING BEFORE PROCEEDING AND DO NOT PROCEED IF ANY OF THIS MAKES YOU UNCOMFORTABLE**
After building the firmware image, the image must be converted to Intel Hex format. I like the bin2hex tool found [here](https://grumpf.hope-2000.org) (page is in German). Build the ``bin2hex`` binary and execute: ``bin2hex of816-neon.bin > of816-neon.hex``
Once you have the .hex file, you will need to use the [Neon firmware loader](https://hackaday.io/project/164325-neon816) to install the image. This requires an FTDI cable connected to the 3.3V UART header on the Neon816 system board.
To back up the original firmware, you will need to add an additional command routine to neonprog.cpp (add it after the write command):
```
else if(!strcmp(cmd,"dumprom")) {
char* fn=strtok(nullptr," ");
char buf[0x40];
if(!fn) return;
auto st=Releaser(
fopen(fn,"w"),
[](auto f){if(f) fclose(f);});
if(!st) {
printf("Could not open file\n");
return;
}
for (int addr=0x200000; addr<0x220000; addr+=sizeof(buf)) {
writeHex(addr>>16,2); writeChar(':');
writeHex(addr,4); writeChar('#');
for (int i=0; i<sizeof(buf); i++) {
writeChar('@');
unsigned char c=readByte();
buf[i]=c;
}
fwrite(&buf, sizeof(buf), 1, st);
printf("%08X\n",addr);
}
}
```
then start neonprog with ``neonprog /dev/ttyUSBx`` (replace device with actual serial device for FTDI cable.
From within neonprog, execute ``dumprom backup.bin`` to save an image of both ROM banks to ``backup.bin``.
Once the backup has finished (it will take a while), you can proceed to the installation of OF816 with ``flash of816-neon.hex``. This will also take a while. When it is done, reset your Neon and OF816 should start.
## Restoring the Original NeonFORTH Firmware
Since the Neon (at the time of this writing) only ships with the first bank of flash occupied, first, split your backup with ``split backup.bin``. This will output two files, ``xaa`` and ``xab`` that are bank $20 and bank $21, respectively. Then run ``hex2bin xaa > neonforth.hex``. You can then flash this with neonprog using ``flash neonforth.hex``. Once it's done, reset your Neon and you should see the original firmware running.

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@ -1,7 +1,12 @@
#!/bin/bash
set -e -x
ca65 -I ../../inc Neon816.s -l Neon816.lst
ca65 -I ../../inc romboot.s -l romboot.lst
../../build.sh Neon816
ld65 -C Neon816.l -S 0x8000 Neon816.o ../../forth.o -m forth.map -o forth
ls -l forth
ld65 -C Neon816.l -S 0x8000 Neon816.o ../../forth.o ./romboot.o -m forth.map -o of816-neon.bin
ls -l of816-neon.bin
if which -s bin2hex; then
hex2bin of816-neon.bin > of816-neon.hex
ls -l of816-neon.hex
fi

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@ -7,7 +7,7 @@
phx
asl
tax
jmp (table,x)
jmp (.loword(table),x)
table: .addr _sf_pre_init
.addr _sf_post_init
.addr _sf_emit
@ -34,8 +34,19 @@ table: .addr _sf_pre_init
.proc _sf_pre_init
; NeonFORTH does this, presumably to initialize the serial port
sep #SHORT_A
.a8
lda #$8D
sta f:SERctrlA
lda #$06
sta f:SERctrlB
lda #$00
sta f:SERctrlC
rep #SHORT_A
.a16
plx
jmp _sf_success ; we'll see what we need to do
jmp _sf_success
.endproc
.proc _sf_post_init

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@ -0,0 +1,46 @@
.p816
.a16
.i16
.include "macros.inc"
.include "./Neon816-hw.inc"
.segment "ROMBOOT"
.proc romboot
clc
xce
rep #SHORT_A|SHORT_I
.a16
.i16
lda #$01FF
tcs
; Set up MMU for bank 0
ldx #$001C
lda #$8000
: sta f:NeonMMU,x
dex
dex
bpl :-
jml f:Neon_ROM
.endproc
.segment "VECTORS"
.proc vectors
; native mode vectors
.word $FFFF ; FFE0 - reserved
.word $FFFF ; FFE2 - reserved
.word $FFFF ; FFE4 - COP
.word $FFFF ; FFE6 - BRK
.word $FFFF ; FFE8 - ABORT
.word $FFFF ; FFEA - NMI
.word $FFFF ; FFEC - reserved
.word $FFFF ; FFEE - IRQ
; emulation mode vectors
.word $FFFF ; FFF0 - reserved
.word $FFFF ; FFF2 - reserved
.word $FFFF ; FFF4 - COP
.word $FFFF ; FFF6 - reserved
.word $FFFF ; FFF8 - ABORT
.word $FFFF ; FFFA - NMI
.word .loword(romboot) ; FFFC - RESET
.word $FFFF ; FFFE - IRQ/BRK
.endproc